New CO2 ocean sequestration method created

Nov 7, 2007 - UPI

U.S. scientists have developed a technology that enhances removal of carbon dioxide from the atmosphere and stores it in Earth's oceans.

Researchers from Harvard and Pennsylvania State Universities said their method -- unlike other ocean sequestration technologies -- doesn't make oceans more acidic and might be beneficial to coral reefs.

"Essentially, our technology dramatically accelerates a cleaning process that nature herself uses for greenhouse gas accumulation," said Harvard graduate student Kurt Zenz House.

In natural silicate weathering, carbon dioxide from the atmosphere dissolves in fresh water and forms weak carbonic acid, he said. As the water percolates through the soil and rocks, the carbonic acid converts to a solution of alkaline carbonate salts. That water eventually flows into the ocean and increases its alkalinity.

An alkaline ocean can hold dissolved carbon, while an acidic one will release the carbon back into the atmosphere, the scientists said.

"In the engineered weathering process we have found a way to swap the weak carbonic acid with a much stronger one (hydrochloric acid) and thus accelerate the pace to industrial rates," said House.

The research is detailed in the journal Environmental Science and Technology.